In conventional reciprocating engines, the straight-line movement of pistons and parts is conveyed to the rotational movement of the crankshaft, which tends to produce energy loss due to poor rotational dynamics, and to sudden mass accelerations in the pistons and related parts. Because of the "stop-start" nature of the piston and connecting link action, considerable energy loss, wear and frictional forces are encountered, which tend to draw energy away into non-useful heat and to produce wear and degradation which, if eliminated, would lengthen the left of engine parts and improve efficiency.
Many radial engine designs have been devised in the past. However, most such designs do away with the piston/cylinder concept altogether, and replace the combustion chamber with various forms of dynamic chambers defined between sliding or rotating members, the geometry being such as to increase and decrease the size of the combustion chamber. Such conventional radial engines have all encountered a number of problems in their development, with the result that few if any radial engine designs are commercially used in the automobile market at the present time in North America.
My co-pending U.S. Patent Application Ser. No. 376,695, filed May 10,, 1982 and entitled "Improvements in Internal Combustion Engines" provides an advantageous and novel structure which combines the radial engine concept with the practicality of a piston. More specifically, the invention described in my co-pending application is one which allows rotational movement to enhance the intake of the combustible mixture and the exhaust of combustion gases, to move lubricating oil in a preferential direction, and to facilitate valve movement. In the device described in my co-pending application, the design is such that the piston when under pressure moves away from centre.
More particularly, the invention described in my co-pending application provides a rotary frame carrying three cylinder/piston combinations spaced at 120.degree. intervals, the machine dynamics being arranged in such a way that the pistons, while indeed reciprocating with respect to their individual cylinders, nonetheless when viewed from a stationary frame of reference are seen to move in a substantially circular path, thus reducing acceleration forces on the piston to a minimum, and contributing to an extremely smooth operation. Furthermore, the pistons are arranged so that they fire out from center (with the centrifugal force). Moreover, the connecting rods undergo primarily a circular movement, although with a superimposed wobble. Finally, the eccentric portion of each crankshaft also travels in a substantially circular motion.
While the engine described in my co-pending application functions quite satisfactorily, there are certain limitations on its maximum speed due to the use of belts or chains for the valve timing sequence. Centrifugal forces in these elements place an upper limit on the speed at which the engine can rotate.